City's sewer overflow plan comes up short

A plan worked out with state and federal authorities should go further toward protecting the environment and the investment of taxpayers in clean water.
Crosscut archive image.

Duwamish River outfall

A plan worked out with state and federal authorities should go further toward protecting the environment and the investment of taxpayers in clean water.

People who live in Seattle, King County, and the rest of the Puget Sound region appreciate a clean environment and clean water. For us, our children and our grandchildren, we value safe swimming beaches, fresh local seafood, and abundant wildlife. Fortunately for us, clean water is also the law.

The year 2012 marks the 40th anniversary of the federal Clean Water Act. The act created for the first time a national mandate to protect and restore all waters to be safely swimmable and fishable, with waters so designated to be safe for drinking as well. In the process the act recognized that our waters are held in the public trust and no one has the right to pollute the water to the detriment of others. It has given us much to celebrate over the past four decades — including safer drinking water, improved sewage treatment, strict standards on industrial discharges and rivers that no longer catch fire, as the Cuyahoga River famously did in 1969.

This year we also can point to another success story in the making: Seattle and King County are close to finalizing consent decrees for their combined sewer overflow (CSO) systems. Can it really be a success story to be 40 years late in approving a long-term (13 to 18 year) plan to control a major source of pollution? You bet, we say. Better late than never.

It's important, however, for the consent decrees to go significantly further than they would do as now proposed in one key area: the treatment of toxic organic chemicals in combined sewer overflows and stormwater. Unless the local, state, and federal leaders involved in the consent decree step up to that issue, we will be doing too little for both current generations and those in the future.

Combined sewer overflows — or CSOs — are dirty and dangerous. Hundreds of times a year, to the tune of nearly a billion gallons a year just in the Seattle area alone, this mixture of untreated sewage, industrial wastewater, and polluted street runoff spews into Puget Sound, Elliott Bay, the Duwamish River, the Ship Canal, Lake Union, and Lake Washington. CSO incidents occur during peak rain events when stormwater flows into our combined sewer system and overwhelms the capacity of the pipes and discharging at designed “relief valves,” or CSO outfalls.

The combined sewer system for the entire Seattle area is integrated into one interconnected system, but Seattle and King County separately “own” individual CSO outfalls. Seattle has 92 outfalls, of which 45 are controlled to the state standard of one or less overflow event per year, on average for a total annual flow of about 190 million gallons (2010). King County has fewer but larger outfalls - 38 in total, of which 13 are considered to be controlled. These include a much larger amount of flow (about 800,000,000 gallons per year). According to Seattle’s 2010 control plan, about two-thirds of Seattle is served by a combined or partially separated sewer system (971 miles of sewer) and environmentally safer separated storm and sewer systems serve the other one-third (455 miles of sewer).

Controlling CSOs is a national priority, with over 700 systems in need of work to protect their waterways. All over the nation, communities are finding ways to deal with the problem and the Environmental Protection Agency is stepping in to negotiate consent decrees (an agreement with the force of a court order) with many municipalities that have CSO systems to ensure the work gets done. New York City, Philadelphia, and Indianapolis have all begun work under their agreements. Closer to home the cities of Portland, Snohomish, and Bremerton have actually completed their major CSO infrastructure projects, with each already achieving impressive results.

When not properly controlled or treated, the pollution from these overflows threatens human health, reduces recreational opportunities and poisons the aquatic food chain with toxic chemicals, some of which persist for decades and accumulate up the food chain. Ultimately this is our waste and it’s up to us to deal with it.

It may be tempting when confronting difficult pollution problems to suggest that we just deal with the biggest problems first, and wait on the rest. But what constitutes a “biggest” problem?  Some people have observed that stormwater pollution — water that drains streets, rooftops, parking lots and industrial sites, without mixing with sewage and wastewater — is well documented as the leading overall source of toxic pollution to the Sound. Seattle’s study shows that 8,200 tons of toxic chemicals are transported by stormwater annually. They may suggest this as a reason for delaying or weakening CSO requirements, in favor of putting more effort toward controlling stormwater runoff.

Controlling stormwater is very important. However this analysis misses several key points. First, combined sewer overflows are incredibly damaging on a local level. While stormwater is everywhere, CSOs happen at a few specific locations where they can have significantly higher toxic and bacterial loading than straight stormwater. If you average a problem out over a large area, it does not reduce the severity of the immediate impacts in front of the outfall.

CSOs are essentially stormwater plus industrial wastewater and domestic sewage. This includes the toxic chemicals that accumulate in the sediments and muds near the outfall and get into our fish and wildlife as well as bacteria and other pathogens from human waste. Because of the high risk they pose, CSOs are regulated as wastewater and subject to stricter standards under the Clean Water Act than stormwater runoff, which means that discharges must be controlled to protect aquatic life, recreational opportunities, and human health.

Pollutants in wastewater and in stormwater, while there is some overlap, are different. A key problem with CSOs is the presence of toxic organic chemicals, which accumulate in the muds and get into our fish and wildlife.

Toxic organic chemicals, however, are omitted from the list of chemicals to consider in the consent decree between the EPA, the state Department of Ecology, and the City of Seattle that is on the verge of being voted on by the City Council.  A similar consent decree is expected for King County later this summer.

Water quality data collected from King County CSOs in the past five years show that the flows contain toxic heavy metals such as mercury and lead, as well as toxic organic chemicals such as polychlorinated biphenyls (PCBs), phthalates (plasticizers), biphenyl-A (chemical that hardens plastics), 1-4 dichlorobenzene (fumigant and toilet deodorant), polycyclic aromatic hydrocarbons (PAHs from automobile exhaust and industrial sources), phenol, and dioxins/furans (one of the most toxic chemicals we find in Puget Sound). In addition, CSO flows include other typical raw sewage constituents such as oxygen-depleting nutrients, bacteria, viruses, and other human pathogens.

Toxic chemicals tend to bind to the small particles in the flows — the reason the flows look murky rather than clear — and these particles settle out when the CSOs discharge to the quieter water in the lakes, rivers, and the Sound. According to data assessments by state Ecology, the city, and the county, the list of toxic chemicals that have accumulated in the sediment near these outfalls is large and includes: PCBs, PAHs, benzoic acid, 4-methyl phenol, phthalates, benzyl alcohol, methylene chloride, carbozole, dibenzofuran, tributyltin, mercury, lead, arsenic, silver, and zinc. This is a nasty stew of chemicals, often in concentrations above cleanup standards. These chemicals end up contaminating the small organisms that live in the sediment and mud, which are then eaten by small fish, which are in turn eaten by bigger fish and get magnified by many times  on up to the top of the food chain —  severely impacting our seals, orcas, eagles, osprey, and potentially people who eat local fish.

Where does this toxic pollution come from? The raw sewage part of the CSOs includes toxic pollutants from our homes such as cleansers, pharmaceuticals, and other products that get washed down the drain. Another large load comes from the 64 industrial and commercial facilities that contribute 860,000 gallons of caustic, petroleum and/or metal-laden, or other toxic wastewater to the combined sewer system daily (according to King County’s 2009 West Point Sewage Treatment Plant permit). This is combined with stormwater flows containing oils, heavy metals, and muck from our roads. In some cases, the sediments and muds around the outfalls still bear traces of historic industrial sources or old spills.

What about stormwater pollution? As mentioned earlier, stormwater is a major constituent of CSO discharges. The Department of Ecology recently completed a series of regional studies of pollutants in stormwater. They found that stormwater runoff has elevated levels of copper, lead, zinc, mercury, PCBs, phthalates, petroleum products, PAHs, and some pesticides, with much higher levels coming from commercial/industrial areas than in residential areas. Copper and zinc come from brake and tire wear, PAHs from fuel combustion, and petroleum from motor oil drips and leaks as well as refueling operations. Cadmium, copper, and zinc and possibly phthalates come from plastic pipes and zinc coated pipes fences and sign posts, and roofing materials. These same pollutants are present in CSO discharges thanks to the stormwater flows that mix with the wastewater.

We are currently well into the process of cleaning up the Duwamish River and East Waterway, which are federal Superfund sites and two of the most toxic waterways in the country. When done we will have invested hundreds of millions of dollars to clean up these two sites from a legacy of industrial activity and our ongoing pollution:  PCBs, PAHs, arsenic, dioxin/furans, and 40 other toxic organic chemicals and metals that are currently in the sediments and muds at levels above federal and state cleanup standards. Lake Union and the Ship Canal are also contaminated with high levels of similar pollutants but have not yet been designated as Superfund sites. Do we really want to put the success of the cleanups in jeopardy by repolluting the river with CSO discharges? This is in fact already happening at one early-action priority cleanup site near the Duwamish-Diagonal CSO outfall. If this is allowed to continue throughout the river, it could put taxpayers on the hook for future cleanup.

There is also an environmental justice issue. Many CSO outfall locations are in environmental justice communities that are less affluent and more ethnically diverse and bear the brunt of a toxic history such as the Duwamish Valley. In some cases the same areas support a higher reliance on harvesting local seafood for subsistence. And Native American tribes have cultural resources in these areas; they also have treaty rights in some of these spots or actively fish, or both.

In these areas, however, even the act of fishing is unsafe because of CSO discharges, let alone the safety of the catch. Nearly every outfall in Seattle has a sign warning not to swim or fish after a significant rainstorm due to the possibility of a sewage overflow.

The key strategies for tackling these problems include reducing the amount of water flowing into the system, expanding the capacity of the system to handle peak flows, and finally, treating CSOs when overflows are unavoidable.

The systems being proposed incorporate a combination of “green” and traditional “gray” infrastructure to account for the challenges of the built environment plus emerging technologies. Green Infrastructure like rain gardens, bioswales, porous pavement, and green roofs is a key part of the solutions and is promoted by the EPA-Ecology-City Decree, reflecting the leadership of the Pacific Northwest in this area. These features in the urban core of our city allow for reducing both the flow of stormwater and also the load of water in the combined sewer pipes, thus reducing the chances of an overflow during big storms. Where possible, it is ultimately far cheaper and more effective to filter the water on-site.

Another important method — although outside of the CSO Control plans — is source control by removing the most dangerous chemicals so they aren’t used in the first place, To that end, Washington has led the nation in passing important bills to phase out the use of toxic chemicals in products (flame retardants in computers and textiles, lead and phthalates in toys, copper in brake pads and in boat paint, and lead in wheel weights). Passing these kind of laws combined with education to reduce the use of dangerous chemicals is highly effective in keeping pollution out of our CSOs and out of stormwater. We need more of this kind of pollution prevention because until we implement these source control and green infrastructure solutions at a large scale, we will be forced to pay for and build more expensive engineered facilities to treat our runoff.

Much has been made about the ultimate price tag for finishing the job, estimated at $711 million for the county and $500 million for the city, which will be spread out over many years as is typical for large public works projects. The estimates by the City and County show costs rising moderately at first, and ultimately by the year 2025 amounting to around $7 a month additional for county households on the regional sewer system and roughly twice that for city households that pay into both systems through the wastewater utility. In the context of expensive highways, tunnels, bridges, arenas, or maybe a premium coffee beverage a few days a week, this is something we can indeed afford, and must do to control our waste.

Important questions are: Who pays? And what are the costs of delay? Delay in addressing an issue like toxic chemicals transfers the cost from those who are polluting today to those that will live here in the future. With continual introduction of new toxic chemicals and with increased population the next generation will have even more costs to deal with contaminated CSOs and stormwater. It is not fair to ask the next generation to clean up after our mess. Delay increases the cost of the treatment that will ultimately be required anyway. Delay also increases the costs of the additional restoration that will be needed, increases the costs resulting from increased health and safety risks, and reduces the value of natural resources used by future residents. These costs should be included in any cost assessment. So postponing the cost of treatment does not reduce costs or save money.

It is important to note that money spent on these projects is not going simply down the drain. CSO projects will in fact create jobs (as many as 1,400 green jobs, according to King County’s analysis) and support quality local businesses in the process, thereby helping to rebuild our local economy and infrastructure at the same time. You can’t outsource offshore a plumber after all, and this is nothing if not a big plumbing project. This investment will also restore our valuable resources and the cultural and economic benefits they offer.

For the first time the EPA is introducing an integrated approach that will create additional flexibility for the cities and counties across the US to plan around CSO and stormwater requirements in order to prioritize the highest-benefit projects and to ensure that all work will be completed to meet all Clean Water Act standards. This feature is incorporated in the Seattle CSO Consent Decree and is expected in the upcoming King County Consent Decree.

A rush to take this flexible approach is worrisome if it is all about holding down the amount of money invested rather than ensuring that water quality standards are met, recreation and human health are protected, and our waters and wildlife populations are restored to health.

This effort can be a win-win, however, if high quality science is brought forward and new data are collected at the outfalls (CSOs and stormwater) to illuminate the impacts on the sediments and muds and the aquatic organisms that live there from all pollutants, including organic chemicals. The city and county should implement programs to obtain this information now so that strong science-based decisions can be made. Importantly, the consent decree needs to be corrected to include assessments of toxic organic chemicals as these are the very chemicals that are of concern to our aquatic wildlife with regard to CSO and stormwater pollutants.

To protect human health and aquatic life and to recover the natural resources of a healthy Puget Sound the protections assured under the federal Clean Water Act must be honored, and plans to control the combined sewage overflow problem must be approved and effectively implemented along with polluted stormwater runoff programs. Beyond improving the consent decree, we need to pass laws to reduce dangerous pollution sources (such as the recently passed phaseout of copper in brake pads). We need to expand programs to construct green infrastructure projects that reduce stormwater inflow in the CSO drainage areas (including the city’s ”Rainwise” program for homeowners) as well as in our separated stormwater systems.

The city and county have already shown strong leadership on these approaches and we urge the citizenry to help us all work together to get this part of job done to restore the health of Puget Sound.


Please support independent local news for all.

We rely on donations from readers like you to sustain Crosscut's in-depth reporting on issues critical to the PNW.


About the Authors & Contributors